In order to keep the third generation mobile communication system to be competitive in the communication field, the 3rd Generation Partnership Project (3GPP) standard working group is working on the research of the Evolved Packet System (EPS). The entire EPS system mainly includes two parts: an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) and an Evolved Packet Core (EPC). The EPC of the system can support the access of a user from a Global System for Mobile communication (GSM) system/Enhanced Data Rate for GSM Evolution (EDGE) Radio Access Network (GERAN) and a Universal Terrestrial Radio Access Network (UTRAN).
An EPC packet core network contains a Home Subscriber Server (HSS), a Mobility Management Entity (MME), a Serving Gateway (S-GW), a PDN Gateway (P-GW), a Serving GPRS Support Node (SGSN) and a Policy and Charging Enforcement Function (PCRF), wherein:
the HSS is a permanent storage site of user subscription data and is located in a home network subscribed by the user;
the MME is a storage site of the user subscription data in a current network and is responsible for signalling management from a terminal to a network non-access stratum (NAS), the tracking and paging management function in a user idle mode and bearer management;
the S-GW is a gateway between a core network and a radio system and is responsible for user plane bearer from a terminal to the core network, data cache in a terminal idle mode, the function of a network side initiating a service request, lawful interception, and packet data routing and forwarding function;
the P-GW is a gateway between an evolved packet domain system and an external network of the system and is responsible for functions such as IP address allocation of a terminal, charging function, packet filtering and policy application;
the SGSN is a service supporting point for users of GERAN and UTRAN to access an EPC network, which is similar to the MME in function. It is responsible for functions such as the update of user's location, paging management and bearer management; and
the PCRF is responsible for providing policy control and charging rules to a Policy and Charging Enforcement Function (PCEF).
In some scenarios, the concept of relay node is introduced in order to enlarge the radio coverage range or temporarily increase the capability of wirelessly providing access users. The schematic diagram of the network architecture is as shown in FIG. 1, and the description of network elements is provided as follows:
A Relay Node (RN) contains two parts of functions, User Equipment (UE) and a relay node. The RN on the one hand serves as a UE to access the network and performs operations such as bearer establishment, and on the other hand serves as an E-UTRAN NodeB (eNB) to provide access for the UE.
The Donor eNodeB (DeNB) provides radio access for the RN, ends a radio resource control (RRC) signalling of the RN-UE and ends an S1 AP signalling and an X2 signalling of the RN-eNB. The SGW and PGW of the RN-UE are built in the DeNB.
The Relay Node Operator and Management (RN OAM) system is used for the RN to acquire necessary connection information therefrom.
The main purpose for the operator to deploy the architecture is to enlarge the coverage range of a base station by deploying relay nodes in some places where it is inconvenient to deploy wire connections, for example, in a remote underdeveloped region or an unexpected big conference or match. Moreover, in such a scenario, the location of a relay node is generally fixed. However, with the application of the relay node, the operators consider applying this technology to a broader scenario. For example, on a high speed railway, since a train is moving in a high speed, a large amount of wire communication facilities need to be deployed along the lines of the train, and this greatly increases the deployment cost for the operators. The radio link between a relay node and a donor eNodeB can just reduce this cost, and is thus popular with the operators. Such a device is called a mobile relay. See FIG. 1. Particular properties of a high-speed train scenario are as follows:
The train is moving at a high speed, such as 350 km/h; (an European Eurostar train has a length of 393 meters and a speed of 300 km/h; a Japanese Shinkansen has a length of 480 meters and a speed of 300 km/h; and a Chinese high-speed train has a length of 432 meters and a speed of 350 km/h);
running along a fixed line;
the signal penetration loss of a train carriage is high; and
the users on the train are in a static state relative to the train or moving at a walking speed.
The particularity of the current MR usage scenario is considered, that is, usage on a high-speed train. The implementation of automatic neighbor optimization by an MR can be considered from the following aspects:
Since the MR only serves high-speed train users, in the train running process, a source DeNB has certain switching target cells with regard to the MR; and in the train running process, the users under the MR are relatively static and also do not need separate switching, and thus it can be considered that, in the train running process, the MR does not need to execute Automatic Neighbor Relation (ANR) measurement when being taken as a UE and also does not needs to maintain a Neighbor Relation Table (NRT) when being taken as an eNB. Here, the ANR mainly considers the condition where the MR is taken as an eNB. Thus, for the MR, only when the train reaches the station and stops, there exists the demand that the users under the MR need to migrate to an external macro cell, and therefore user migration needs to be implemented relying on the neighbor relations.
The difference from the Long-Term Evolution (LTE) ANR: ANR measurement of an MR only needs starting at specific moments, while the LTE ANR measurement has no starting limitation. During the train running process, no NRT table needs to be saved and maintained on the MR, that is to say, the ANR function is not needed. There is no effective solution for an MR in a mobile environment (for example, a high-speed train running environment) to achieve the automatic generation and optimization of neighbor cells. Therefore, in a scenario of mobile relay node deployment in a mobile environment (a high-speed train environment), how to ensure the implementation of automatic generation and optimization of neighbor cells by mobile relays is a problem needing to be solved.
For the above-mentioned problem in the related art, no effective solution has been provided.